Liquid metals formed by alloy of gallium, indium and stannum are known for having a low melting point and are innocuous, thus has been replaced with mercury in the industrial field. In this case, adhesive property of liquid metal formed by alloy of gallium, indium and stannum has been a major impediment. Liquid metals are an eutectic alloy and highly reactive to other substances, thus is difficult to remove once adhered to the surface of other substances. For this reason, it is necessary to treat the surfaces by coating with oxides such as gallium oxide or titanium oxide for repelling liquid metal (preventing from getting wet).
The techniques for forming the liquid-repellent surface (non-wetting surface) to repel liquid metal are disclosed in, for example, Patent Documents 1 and 2 below. It is a technique to form a film of oxides such as titanium oxide or aluminum oxide by a method such as physical vapor deposition (PVD) for forming a liquid-repellent surface having the liquid-repellent action of the oxide film. The technique also forms an oxide layer on the surface of a base material for forming the liquid-repellent surface having the liquid-repellent action of the oxide layer.
Patent Document 1: JP-A-H8-55595
Patent Document 2: JP-A-H11-93946